OHRYSOBOTJIRIS FKMORATA, 



110 



CHRY80BOTHRIS femorata — Fabr. (The Flat-headed Apple-tree borer.) 



This species is of a dark, dull greenish or 

 dark grayish color, with a strong copper lustre, 

 the whole upper surface having the appearance 

 of being sprinkled with an ash-colored powder, 

 the under side and limbs of a brilliant coppery- 

 color, the feet green. The head is immersed in 

 the thorax to the eyes. Length usually about 

 half an inch, but there is considerable varia- 

 tion in size. 



The usual length of the larva is about seven- 

 tenths of an inch. It is soft, flesh-like, and of 

 a pale yellow color*. The head is small and 

 deeply immersed into the following segment ; 

 the jaws black. The third segment is very 

 Faix— Fiat-headed borer of the broad and large, being nearlv twice the width 

 rr!«!iarVaf c ?Lwio?iarva; of any of the posterior segments ; it is rather 

 underside; b, pupa ; a, beetle, broader than long, having on the upper side a 

 large oval callous-like elevation covered with numerous brown raised 

 points. 



The eggs, according to Prof. Riley, are pale yellow, and irregularly 

 ribbed or corrugated, ovoidal, with one end flattened and 0.02 of an inch 

 in length ; they are usually glued by the female under the loose 

 scales or within the cracks and crevices of the bark, several of them 

 being not unfrequently found together. The young larvae hatched 

 from these gnaw their way through the bark, and gradually, as it 

 grows, extends its broad and flattened channel next the bark, gird- 

 ling the smaller trees. At length, jvhen it has grown stronger and 

 its jaws firmer, it bores into the more solid wood of the tree, working 

 upward until about to undergo its transformation, when it cuts a 

 passage to the outside, leaving a thin covering at the surface through 

 which the beetle afterwards forces its way. The beetle usually makes 

 its appearance in May or June. 



It is subject to the attacks of several parasites, some of which, 

 •though not specifically determined, belong to the Chalcididse, an exten- 

 sive family of small four-winged wasp-like flies, which probably 

 deposit their eggs in the larva?, and from which small white grubs 

 about the tenth of an inch long are produced, which finally destroy 

 their host. Prof. Riley has discovered two other parasites belonging 

 to the Ichneumon family, also wasp-like insects. One, which he 

 names Bracon charus, is about one-third of an inch long, without the 

 -ovipositor, which is a little longer than the body. The abdomen vs 

 red, the rest black, the wings being a deep smoky color, with a faint 

 zig-zag clear line across the middle from the stigma. The other spe- 

 cies is the Cryptus grallator of Say, in which the general color is 

 brownish yellow, the wings being marked with two dusky or smoky 

 patches on each. Length of body about half an inch, ovipositor 

 scarcely a third of an inch long. When ants can penetrate their 

 •burrows they usually destroy them. 



The flat-headed borer, although more injurious to the apple than 

 Any other cultivated tree, attacks a number of both native and cul- 

 tivated species its favorite in the natural state appears to be the oak, 



